1. Field of Invention
The present invention relates to an osteoimplant for use in the repair, replacement and/or augmentation of various portions of animal or human skeletal systems and to a method for manufacturing the osteoimplant. More particularly, this invention relates to an osteoimplant made up of a solid aggregate of bone-derived elements that are bonded to each other through chemical linkages formed between their surface-exposed collagen.
2. Description of the Related Art
The use of autograft bone, allograft bone or xenograft bone is well known in both human and veterinary medicine. See Stevenson et al., Clinical Orthopedics and Related Research, 323, pp. 66-74 (1996). In particular, transplanted bone is known to provide support, promote healing, fill bony cavities, separate bony elements such as vertebral bodies, promote fusion and stabilize the sites of fractures. More recently, processed bone has been developed into shapes for use in new surgical applications, or as new materials for implants that were historically made of non-biologically derived materials.
U.S. Pat. No. 4,678,470 describes a non-layered bone grafting material produced from bone by a process which includes tanning with glutaraldehyde. The bone may be pulverized, used as a large block or machined into a precise shape. The tanning stabilizes the material and also renders it non-antigenic. The bone material may also be demineralized.
Collagen is a naturally occurring structural biomaterial and is a component of connective tissues, including bone, in all vertebrate species. Native collagen is a glycine-rich chain of amino acids arranged in a triple helix and can be crosslinked by a variety of procedures.
Tissue transglutaminase is described as being effective at increasing adhesive strength at a cartilage-cartilage interface. See Jurgensen, K., et al., The Journal of Bone and Joint Surgery, 79-A (2), 185-193 (1997).
U.S. Pat. No. 5,507,813 describes a surgically implantable sheet formed from elongate bone particles, optionally demineralized, containing biocompatible ingredients, adhesives, fillers, plasticizers etc.
U.S. Pat. No. 4,932,973 discloses an artificial organic bone matrix with holes or perforations extending into the organic bone matrix. The holes or perforations are indicated to be centers of cartilage and bone induction following implantation of the bone matrix.
U.S. Pat. No. 4,394,370 discloses a one-piece sponge-like bone graft material fabricated from fully demineralized bone powder or micro particulate bone, and reconstituted collagen. The sponge-like graft is optionally crosslinked with glutaraldehyde.
Another one-piece porous implant is described in U.S. Pat. No. 5,683,459. The implant is made up of a biodegradable polymeric macrostructure, which is structured as an interconnecting open cell meshwork, and a biodegradable polymeric microstructure composed of chemotactic ground substances such as hyaluronic acid.